The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 22, 1980
Filed:
May. 24, 1978
Applicant:
Inventor:
Bert G Levefelt, Sandviken, SE;
Assignee:
Sandvik Aktiebolag, Sandviken, SE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175317 ; 175318 ; 175339 ; 166325 ; 137541 ; 137549 ;
Abstract
A check valve for a rock drill comprises a valve plate carrying a cylindrical strainer. An insert is carried by the valve plate and is movable between valve-open and valve-closed positions. A spring biases the insert to a valve-closed position. The insert unit includes a lid which engages and covers the top of the strainer in a valve-open position, and a bottom plate which covers the valve plate in a valve-closed position to prevent cuttings from fouling the valve mechanism.